Method of making valves



Oct. 4, 1938. R. JARDlNE :2,131,953

METHOD OF MAKING VALVES Filed 0G17. 14, 1951 IIIIIIIIAI l Patented Oct.4, 1938 PATENT OFFICE METHOD oF MAKING vALvEs Robert Jardine, DetroitMich., assignor, by mesne assignments, to Eaton Manufacturing Company,Cleveland, Ohi

o, a corporation of Ohio Application October 14, 1931, Serial No.568,771

2 Claims.

'Ihis invention relates to valves and more particularly to the poppettype of valve used in internal combustion engines.

One object of the invention is the provision of a valve having a hollowsteel head portion filled with material such as copper having superiorheat conducting properties.

Another object of the invention is the provision of a valve having asteel shell portion formed by swaging the steel when filled with aductile material.

Another object of the invention resides in the method of making a valvein which a steel bar is drilled, the hole being subsequently filled witha ductile heat conducting material, the lling material being swelled outin the valve head by a forging operation to provide a hollow steel headhaving a filling of the heat conducting material.

Other objects and advantages of the invention will be apparent from thefollowing description, the appended claims and the accompanying drawing,in which Fig. 1 is a longitudinal cross-sectional view of a valve formedin accordance with the present invention;

Fig. 2 is a cross-sectional view of the valve body during its course ofmanufacture;

Figs. 3 and 4 are cross-sectional views Vshowing the head end of a valveat diiferent stages of a modified method of procedure; and

Figs. 5 to 9 illustrate different steps in the course of construction ofa valve in accordance with another modification of the method ofprocedure.

Referring more particularly to the drawing by reference numerals, Illdesignates generally a hollow valve adapted to be used in internalcombustion engines, and especially adapted for use as an exhaust valve.In such type of valve it is desirable to conduct the heat rapidly fromthe valve head to the valve stem portion so that the operatingtemperature of the valve head is reduced. In accordance with the presentinvention, the valve comprises a hollow steel shell II, containing alling I2 of a ductile material having superior heat conductingproperties. As shown in Fig. l the filling I2 is flared outwardly withinthe valve head and fills the chamber provided in the valve stem, thehead portion of the filling being of substantially mushroom shape andbeing encased or enclosed in the hollow steel valve head shell indicatedat I3. Since the filling I2 is flared out within the valve head, therewill be a comparatively rapid transfer of heat from the outer steelshell of the head, the intimate contact or bond between the filling I2and the steel shell providing for the effective transfer of heat so thatthe heat may be conducted down to the valve stem and transferred to thevalve guide.

In the construction of the Valve, a steel bar I5 shown in Fig. 2preferably having one end IB of considerably greater diameter than thecomparatively long and thinner end Il, is drilled so as to provide thehole I8 extending from one end part way through the bar. This hole isthen filled with a plug I9 of copper or other suitable material ofsufficient ductility so as to be adapted to the subsequent forgingoperation, and that has superior heat conducting properties. The fillingI9 is preferably applied in the form of a bar which is forced within thehole, the length of this filling material being preferably somewhatshorter than the length of the hole so as to provide a small space 20 atthe outer end of the steel bar, as shown.

The end I6 of larger diameter is then forged so as to provide a valvehead of substantially mushroom shape, the forging operation serving toforce the steel into the space 26 and close this space while at the sametime radially expanding both the copper filling and the steel shellportion to provide a hollow steel head having the lling of copper asshown in Fig.V l. If the space 20 is not completely closed by the steelany small openings may be lled by welding. During the forging step, thecopper filling of the valve head is intimately associated with or bondedor tted to the steel shell to provide for the effective conduction ofheat from the shell to the copper. The heat may therefore be rapidlyconducted away from the head and down to the stem portion of the valveduring operating conditions, even though the steel shell is an alloyparticularly desirable for withstanding the high operating temperaturesand the attacking gases that are present in the engine fuel or productsof combustion.

In accordance with the structures shown in Figs. 3 and 4, the valve head2l comprises the steel shell 22 entirely enclosing and encasing thefilling 23 of copper or the like, the copper filling being flared out inthe valve head to provide for the eective heat transference from thevalve head to the valve stem. The steel shell of the valve 2| may beformed by drilling a steel bar 24 almost but not quite down to thelarger end 25, this end of the valve being subsequently forged afterinserting the bar 26 of copper or similar filling material. The steelshell of the valve head is thus of one-piece integral constructionentirely and perfectly sealing the copper filling within it. The stemmay of course be machined and finished in any desired manner. When usedwith the copper filling the Yspace within the valve head and stem, theeffective heat transfer during operating conditions is provided for.However, if the copper filling is removed after the valve head isVforged, in the manner more fully set forth and claimed in my co-pendingapplication, Serial No. 568,770, filed on even date herewith, theforging of the head when filled with copper is particularlyadvantageous, providing inV a simple way forY a steelshell formation ofthe desired wall thickness.

In accordance with the steps shown in Figs. 5 to 9, the valve is madeina slightly modified manner. 23 designates a steel bar, that isprovided with the bores 29 and 30, preferably produced by drilling thebar part Way from one end to the other. Between the two bores 29 and 3Dthere is a frusto-conical or tapered surface 3|. A filling of copper orother suitable material is then applied, this filling being suitablyshaped so as to fit within both bores, and having a tapered orfrusto-conical surface 33 that fits Ywith the surface 3l in thebar.vThere is an upstanding ring 34 of steel projecting up above the top ofthe filling 32, and this ring is then forged over and around the filling32 so as .to shape and Yclose this end of the filled bar substantiallyas shown in Fig.v 7. The upper end or closed portion of the filled barmay then be flattened by a suitable forging operation so as to provide afiat circular end 35, and thelower end of the bar is then swaged .orforged so. as to reduce its diameter and form a stem 36 as shown in Fig.8, curved outwardly at its upper end as shown at 3l. The valve head isthen forged, being coined to the shape shown in Fig. 9, this forgingstep expanding the copper and the outer steel shell in Whichthe copperis enclosed so as to provide a substantially mushroom shaped copperfilling 38 in the steel shell 39 of the valve head which entirelyencloses it and which is'in close fitting or bonded engagement with itby reason of the forging operation, providing for effective heattransfer from the valve head to the valve stern. In accordance with themethod just described the valve stem and the valve seat can then be ma-vchined and any necessary or desirable heat treatments given.

While the methods herein described, and the form of constructionproduced thereby, constitute preferred embodiments of the invention, itis to be understood that the invention is not limited to these precisemethods and form of construction, and that changes may be made in eitherwithout departing from the scope of the invention which is defined inthe appended claims.

What is claimed is: v,

1. The method of making a valve of the class described comprisingforming a chambered piece of steel, with continuous sides, rounded andim- Aperforate at one end and open at the other end,

providing a counterbored passage of larger diameter at the open end thanat the closed end and with tapering sides joining the passages ofdifferent diameter, making a metal core which is larger incross-sectional area at one end than shaped core encased in steel at thehead end of the valve, and elongating the other end into a Valve stem inwhich the core is enclosed by the steel throughout its length.

2. The method of making a metal filled poppet valve comprising drillinga piece of steel to provide a piece with continuous sides andimperforate at one end and open at the other end, drillingan enlargedaxial' passage at the open end of the steel piece of largercross-sectional area than the passage adjacent the closed end ofthe'piece and tapering the adjacent ends of the passages from one to theother, forming a metal core of good heat conductivity, 'having roundedends and larger in'cross-sectional area at the one end than at the otherto fit within the chamber and axial passage and fitting the same withinthe chamber and the axial passage to leave the open end of the passageunfilled, heating the steel piece and forging'itsV terminal or open endso that it is rounded over the end of the core, forging said parts toflatten said terminal end and to elongate the other end of the compositesteel piece and core into a valve stem in which the core is enclosedthroughout its length in the stem by the steel piece, and forging thefiattened terminal end of the valve to increase the diameter of thesteel and the core at the head end of the valve and provide a mushroomshaped core encased in steel.

ROBERT JARDINE. Y

